<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <script src="../react资料_stu//依赖包/react.development.js"></script>
    <script src="../react资料_stu//依赖包/react-dom.development.js"></script>
    <script src="../react资料_stu//依赖包/babel.min.js"></script>
    <script src="../react资料_stu//依赖包/prop-types.js"></script>
</head>

<body>
    <div id="app"></div>
    <script type="text/babel">
        /* 
      字符串形式的Refs:
        - 给被获取的元素添加一个ref属性,值是字符串(随意命名)
        - 在组件实例上就会有一个ref对象,对象中有一个你设置的字符串属性,值是他代表的DOM
    
    */
        class Parent extends React.Component {
            render() {
                return (
                    <div>
                        <input type="text" ref='oIpt' />
                        <button onClick={this.handle}>点我弹出用户输入的内容</button>
                    </div>
                )
            }
            handle = () => {
                console.log(this);
                const { value } = this.refs.oIpt;
                alert(value)
            }
        }
        ReactDOM.createRoot(document.getElementById('app')).render(<Parent />)
    </script>
</body>

</html>